It's a Fantastic idea. And if any format has to die over time, that will be ODI for sure. T20 is here to stay. I mean you can't kill a format, that gives you the majority of your money, its popular and its a format friendly to spread cricket. What else you need to survive? Test cricket is pure cricket and it promotes skills. ODI is the khichuri of Test and T20. So T20 will always have an upper hand if it has to ever fight with ODI for survival.